Fears that genetic testing will create a new underclass of uninsurable people are unfounded, according to an expert in the field.

The extra health care costs of many genes are less than other risks which insurance companies ignore, such as playing sport, claimed Dr Angus McDonald from the Department of Actuarial Mathematics at Heriot-Watt University.

He has done the first mathematical research on the additional expense facing people carrying a gene which gives an increased risk of Alzheimer's disease. The extra cost was only between 10 and 30%.

Small impact

Dr McDonald: Genes will have less impact than sports

He said: "Genetic tests are likely to have a much smaller impact on insurance premiums than is commonly believed: possibly no impact at all in most cases."

"The debate so far has been characterised more by heat than light but mathematical models can give hard information for policy makers."

However, speaking at the British Association's Festival of Science in Sheffield on Monday, he warned that the information would not make policy decisions any easier.

Who pays?

There are two possible scenarios for the impact of genetic testing in insurance.

Who will pay for the impact of genetic testing on insurance?

If tests results are not used to calculate premiums then people with the risk would be able to buy the insurance, seeing it as a relatively cheap option, which would then hit the insurance company with higher costs when they require health care. Some insurance companies see this as the most likely scenario, which could have catastrophic consequences for the viability of the industry.

Alternatively, if test results are used, some people with high risk may be uninsurable and the government may have to provide protection paid for from general taxation.

Choosing a course of action is a policy decision but Dr McDonald believes that hard data from mathematical models can help the policy makers towards a better choice.

Alzheimer's gene

The gene Dr McDonald considered is called ApoE e4 and people carrying it have an increased risk of Alzheimer's disease in their sixties. His mathematical modelling shows that for around 2% of the population which carries this gene the result will be an increase in their healthcare costs of between 10 and 30%.

This extra risk only puts people on the borderline of having to pay increased premiums. Many other factors in people's lives not considered by insurance companies can carry equal risk.

Dr McDonald said some people are already discriminated against because of their genes, through questions about their family history of, for example, breast cancer or Huntingdon's disease.
But he said the advent of genetic testing would not create new groups of these people. Indeed, if the tests meant that medical care would boost the health of the patient, their long-term health care costs could be reduced.

British insurers currently have a voluntary code of practice which prohibits requesting applicants to have genetic tests. They also have a moratorium on asking for the results of tests already carried out.

But the situation in the US could be very different, said Dr McDonald, because there is no free National Health Service. As insurance pays for nearly all medical care, those companies were much more likely to be sensitive to the risks implied by adverse gene test results.